1. Field of the Invention
The present invention relates to methods for culturing lineage committed human cells, the cells thus obtained, and their uses.
2. Description of the Background
There is significant interest using both early and lineage committed cells for a variety of therapeutic purposes.
In tissue engineering, the goal is to reconstitute fully or partially functioning human tissue in vitro to enable a variety of clerical and other applications. Several studies have been carried out that are aimed at reconstituting functioning human tissues in vitro. Illustratively, the cultivation of human skin has been successful.
The hematopoietic system exemplifies the broad range of cells involved in protection of mammalian hosts against pathogens, toxins, neoplastic cells, and other diseases. The hematopoietic system is believed to evolve from a single stem cell, from which all the lineages of the hematopoietic system derive. Hematopoietic cells have been used in human therapy. Methods and apperati for culturing precursor hematopoietic cells to obtain desired mature hematopoietic cells have been described. See, U.S. Pat. Nos. 5,605,822, 5,399,493; 5,437,994; 5,459,069; 5,635,386, 5,670,147 and 5,670,351.
Adoptive cell therapy is the ex vivo expansion and re-infusion of immune effector cells into human recipients for the treatment or prevention of disease (Rosenberg et al., Science 233, 1318 (1986)). Developments in T-lymphocyte-based adoptive immunotherapy have lead to significant advances in the treatment of metastatic cancer (Rosenberg et al., Science 233, 1318 (1986); Rosenberg et al., N. Eng. J. Med. 319, 1676 (1988); Rosenberg et al., N. Eng. J. Med. 323, (1990)) and viral diseases including Epstein-Barr Virus (EBV) (Heslop et al. 1996), cytomegalovirus (CMV) (Riddell et al., Science 257, 238 (1992)) and human imunodeficiency virus (HIV) (Whiteside et al., Blood 81, 2085 (1993); Ridell et al., Hum. Gen. Ther. 3, 319 (1992)) in humans. Multiple patient populations have been identified in which T-cell therapy has achieved a response rate of approximately 34% after administration of tumor infiltrating lymphocytes (TILs) to metastatic melanoma patients (Rosenberg et al., J. Natl. Cancer Inst. 86, 1159 (1994)). A target human therapeutic dose of 1010-1011TLs is suggested based on extrapolation from studies in mouse tumor models and clinical experience (Topalian et al., J. Immunol. Meth. 102, 107 (1987)). Clinical responses to melanoma tumors have been obtained after expansion ex vivo of TILs in medium containing interleukin-2 (IL-2) and re-infusion of greater than 1011T-cells per treatment cycle together with high doses of exogenous IL-2 (Rosenberg et al., N. Eng. J. Med. 319, 1676 (1988); Rosenberg et al. 1994). The enhanced anti-tumor activity of TILs in vivo compared to lymphokine activated killer (LAK) cells or NK cells may be a function of several complex processes including the ability of these T-cells to proliferate and release an array of lymphokines, to recirculate and accumulate at sites of tumor growth, and to specifically recognize and lyse autologous tumor cells (Pockaj et al. 1994; Rosenberg et al. 1994).
Dendritic cells (DCs) are highly specialized bone-marrow derived antigen presenting cells (APCs) which function as potent stimulating cells for primary T-lymphocyte-mediated immune response. Dendritic cell based immunotherapy is an emerging treatment strategy involving ex vivo expansion and reinfusion of antigen-pulsed or genetically modified DCs into human patients to vaccinate against cancer or infectious diseases. Clinical implementation of these therapies requires the capability of product sufficient quantities of functional DCs for effective patient treatment.
The use of cultured human cells in human therapy has required that a quantity of active cells sufficient to provide a therapeutic effect upon infusion into the patient be used. This has required using culture systems providing large numbers of cells. There is therefore a need for methods for obtaining lineage committed cells with augmented proliferative potential, biological function, or both since such methods would provide more potent cell compositions, capable of being used in smaller amounts in therapy.
Accordingly, it is an object of this invention to provide novel methods, including culture media conditions, for obtaining human lineage committed cells with enhanced proliferative potential, biological function, or both.
It is another object of this invention to provide cultured human lineage committed cells having enhanced proliferative potential, biological function, or both.
These objects and others may be accomplished by a method for obtaining lineage committed human cells having enhanced proliferative potential, biological function, or both. In this method, lineage committed human cells are cultured in any physiologically acceptable liquid culture medium conditions with the liquid culture medium being replaced.